Summary The Bell 206B helicopter operated by Hli-Star Inc., registrationC-GNPI, serial number2353, took off from Boucher Lake at approximately 2015 eastern daylight time, bound for La Tuque Airport, Quebec. The pilot was the sole occupant. Shortly after take-off, the aircraft crashed into Boucher Lake. The pilot sustained minor injuries and the aircraft was substantially damaged. Ce rapport est galement disponible en franais. Other Factual Information The records indicated that the aircraft was equipped and maintained in accordance with existing regulations, and that the pilot was certified and qualified for the flight. He had about 4000hours on theBell206. Photo1. Estimated track of helicopter The meteorological conditions were suitable for visual flight, and the winds were calm. The pilot took off from the outfitter's parking at Boucher Lake, where four passengers had disembarked from the helicopter 30minutes before. At a height of approximately 100feet above ground level (agl), the helicopter commenced its flight in a south-westerly direction. When the aircraft reached translational speed, the pilot noticed that the power turbine rpm (N2) and rotor rpm (Nr) had decreased from 100percent to 95percent and were still decreasing. However, he did not hear the low rpm warning alarm. To reduce power demand and increase rotor rpm, the pilot lowered the collective and at the same time lowered the nose to accelerate. A short time later, the N2 indicator showed 85percent. The pilot, who was then over trees, steered the aircraft toward Boucher Lake, which was on his left. The aircraft descended over the lake and curved around a peninsula. After flying a distance of about one kilometre, a few feet above the lake, the pilot observed an increase in engine rpm in the normal operating range. However, he concluded that, because of the attitude, speed and altitude of the aircraft, the accident was unavoidable. The pilot raised the nose of the aircraft just before striking the surface of the water. Some of the outfitter's residents rescued the pilot a few minutes after the accident. The instrument panel and console were torn off on impact. The overhead circuit breaker panel was bent downward. One of the main rotor blades struck the port side of the fuselage and engine. The main rotor mast failed in over-torque below the rotor head. The transmission shaft couplings failed. The damages observed suggest that the helicopter struck the surface of the lake at a certain speed. No problem with the engine (Rolls RoyceA250-C20B, serial numberCAE83144) was observed or reported before the accident. The engine, fuel flow regulator and fuel governor were examined. Examination of the engine and its components revealed that all damages observed were caused on impact. The engine was receiving fuel and was operating at the time of the collision; no deficiencies that could have caused a loss of power were observed. The investigation did not determine the engine power output at the time of impact. The normal range of engine power output is between 95percent and 100percent of N2. According to the aircraft flight manual, a faulty fuel flow regulator or fuel governor causes a change in power or rpm. In the event of engine underspeed, the pilot should use the collective to maintain engine rpm and prepare for an autorotation landing. The annunciator panel was examined at the TSB Engineering Laboratory. The annunciator panel contained 20annunciator lights. Each light could contain two bulbs. Analysis of the filaments in each bulb established that no lights were on at the time of impact. Photo2. Pilot's shoulder harness straps The pilot was wearing his seat belt, which consisted of a lap belt and shoulder straps connected to an inertia reel mounted on the back panel of the pilot's seat. As a result of the impact, the shoulder straps failed in overload. However, the lap belt remained intact. The pilot unfastened his seat belt before evacuating the helicopter. Although he was wearing a helmet, the pilot sustained substantial head injuries. Examination of the seat belt by the TSB Engineering Laboratory revealed that the shoulder straps were substantially discoloured. There were no signs of rubbing wear or tension. The thickness of the straps was relatively uniform. No date of manufacture was indicated on the shoulder straps; a label on the lap belt indicated that it was manufactured in December1976. Strength testing established that the upper part of the strap failed under 1500pounds of tension and the lower parts failed under 600pounds. The applicable standard, Federal Aviation Administration (FAA) TSOC22, states that a strap two inches in width has a nominal strength of 1500pounds and should not fail below 2250pounds of tension. Seat belts are replaced when they are deemed to be in bad condition. Discolouration is not a criterion for belt replacement. According to the Bell Helicopter's company maintenance manual, proper operation, anchor security and the state of deterioration of belts should be checked on the 100-hour inspection. Transport Canada (TC) issued Airworthiness Notice No.B050, dated 21January2000, to owners, operators and aircraft maintenance specialists concerning the degradation of seat belts due to long-term exposure to sunlight (ultraviolet degradation). However, this notice is under review and is no longer available. The Airworthiness Notice indicated that, in some cases, there has been a significant reduction in the strength of straps less than three years after installation. It recommended that seat belts in the cockpit be replaced if they were manufactured before 27March1987. The Airworthiness Notice further stated that any strap exhibiting signs of discolouration or degradation should be repaired or replaced in accordance with the manufacturer's recommendations. The second edition of Airworthiness Notice No.B050 should be available at the beginning of2005; it will highlight the importance of signs of discolouration. All belts should have been examined on the 100-hour inspection and annual maintenance. They were considered to meet manufacturer's standards. According to the aircraft records, TC inspected the aircraft in March2001 and November2002. The inspection reports indicate that the condition of the seat belts was checked and met the manufacturer's standards. The following laboratory reports were prepared: LP 124/03 - Light Bulb Examination LP 125/03 - Examination of Fractured Shoulder Belt - Bell 206 Jet Ranger LP83/03 - Engine Examination LP89/03 - GPS Examination LP 117/03 - Examination of Fuel Governor Components These reports are available upon request from the TSB.